JINAN, Jan. 21 (Xinhua) -- Amid the harsh winter of the Yellow River Delta, Xing Yan, a resident of the Yellow River estuary, enjoys the warmth at home, where orchids thrive. This comfort is not provided by a boiler, but by harnessing geothermal energy deep in the Earth.

Xing lives in Niuzhuang Township in Dongying District of the city of Dongying, east China's Shandong Province. Beneath the seemingly ordinary town lies a powerful heat source, featuring water temperatures reaching as high as 85 degrees Celsius.

Upon opening the door of the heating facility in the town, an immediate surge of warmth can be felt, thanks to a huge plate heat exchanger that is in operation at this venue. A heat exchange takes place between hot water of 82 degrees Celsius and cold water, resulting in water with a temperature of about 60 degrees Celsius being sent to the town's heating pipelines.

The geothermal heat from underground is, notably, transformed into clean energy that benefits local residents and supports industries, turning Niuzhuang into a warm, smog-free town.

Geothermal heating now covers all 13 urban residential compounds, three rural residential areas and more than 60 institutions in Niuzhuang, totaling 750,000 square meters of heated space. This represents 98 percent of the town's total area, benefiting over 7,000 households, or around 22,000 people. The system helps save 34,000 tonnes of standard coal annually and reduces carbon dioxide emissions by approximately 80,000 tonnes.

As a clean, renewable energy source derived from heat within the Earth, geothermal energy's greatest advantage is its stability. Unlike wind or solar power, it is unaffected by external factors such as seasons, climate or day-night cycles. At the greenhouses of Shandong Shuangfu Flowers Co., Ltd., located in this town, phalaenopsis orchids grow healthily year-round in an environment maintained at about 26 degrees Celsius.

Li Binghai, general manager of the company, said: "After switching to geothermal heating, our costs dropped to around 15 yuan per square meter, which is 25 yuan cheaper than coal heating. The geothermal system provides a stable temperature for our greenhouses, which cover 100,000 square meters, saving us more than 1 million yuan (about 142,753 U.S. dollars) annually in energy costs."

"Geothermal heating not only cuts costs but also enhances stability," Li added. He noted that heating presents a major challenge for flower cultivation in northern China during winter.

In the past, coal heating caused temperature fluctuations, requiring constant manual monitoring. Now, with geothermal heating, the temperature can be controlled via smartphone, extending the flowering period of phalaenopsis and providing stable conditions for developing new varieties. The company currently independently exports flowers to countries like Vietnam, Russia and Uzbekistan.

Shang Xinjian, director of the town's construction service center, said Niuzhuang has established demonstration model for multi-tier utilization of geothemal heat. Hot water of approximately 80 degrees Celsius is extracted from about 1,950 meters underground, with heat exchange equipment then used to warm residential compounds via this source.

The temperature of the tailwater drops to around 50 degrees Celsius, which is routed to the modern agricultural industrial park to heat greenhouses used for growing flowers, fruits and vegetables. Finally, the cooled tailwater is reinjected underground via wells, completing a closed-loop system that conserves both heat and water, according to Shang.

In China, geothermal energy, a stable and controllable form of renewable energy, has been developed for large-scale deployment and diversified applications.

According to figures provided by the China Geological Survey, hydrothermal geothermal resources in the country are equivalent to 1.25 trillion tonnes of standard coal, while the annual exploitable amount is equal to 1.865 billion tonnes of standard coal. China has been leading the world for many years in terms of direct utilization of geothermal energy.

In Niuzhuang, the plan is also being made for using geothermal energy in agricultural products drying and aquaculture in the future, thus helping to establish a complete industrial chain that integrates high-end farming, breeding, processing and leisure.

"The underground treasure trove of geothermal energy will bring more warmth and opportunities to our town," said Song Ke, deputy Party chief and head of the town.